It is well known that the presence of outside rear view mirrors mounted on a motor vehicle body have an aerodynamic effect on the airflow around the vehicle body. In order to reduce the aerodynamic drag of the vehicle body it has been known to mount the mirror within a housing defined by top, bottom and inboard and outboard side walls which diverge angularly from one another to present a tapered shape to oncoming airflow. Although such housing configurations are preferable to a housing presenting a bluff frontal shape to the oncoming airflow, the presence of such mirror housings as an appendage on the exterior of the vehicle body do nonetheless increase the aerodynamic drag relative to a motor vehicle with no exterior rear view mirror at all.
Aside from the aerodynamic considerations of exterior rear view mirrors, the prior art has also addressed the matter of decontaminating the side window adjacent the exterior rear view mirror to prevent a buildup of water or foreign matter which may attach to the side window in the line of sight between the occupant and the exterior mounted rear view mirror. For example, U.S. Pat. No. 4,200,327 by Manfred Wepler issued Apr. 29, 1980 proposes an air deflecting member mounted on the door in conjunction with the mounting of the mirror and providing a deflection of airflow past the side window away from the side window to thereby deflect contaminated airflow away from the side window portion adjacent the exterior rear view mirror.
Still other prior art patents such as U.S. Pat. No. 4,134,612 by Joseph Nelson issued Jan. 16, 1979, and U.S. Pat. No. 4,196,930 by Oscar Busche issued Apr. 8, 1980, provide air deflectors mounted on the vehicle bodies adjacent the rear view mirror for deflecting oncoming airflow onto the viewing surface of the rear view mirror in such a manner as to control the impact of foreign matter against the mirror glass. The shortcoming of these devices is that the addition of such deflecting vanes on the vehicle body adjacent the rear view mirrors work to increase the total frontal area of the vehicle and accordingly may increase the aerodynamic drag.
It would be desirable to provide an aerodynamic rear view mirror for a vehicle body which would be aesthetically pleasing, improve the vehicle aerodynamics and also limit the impingement of foreign matter on the side window and the mirror glass.